''Shidaisaurus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

metriacanthosaurid Metriacanthosauridae is an extinct family (biology), family of Allosauroidea, allosauroid theropod dinosaurs that lived from the Middle Jurassic to the Early Cretaceous. When broken down into its Greek roots, it means "moderately-spined lizards". ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

. Its fossil was found in early

Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...

-age rocks of the

Chuanjie Formation The Chuanjie Formation (), is a geological formation in Yunnan, China. It dates back to the Middle Jurassic.Weishampel, David B; et al. (2004). "Dinosaur distribution (Middle Jurassic, Asia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska ...

Yunnan Yunnan , () is a landlocked Provinces of China, province in Southwest China, the southwest of the People's Republic of China. The province spans approximately and has a population of 48.3 million (as of 2018). The capital of the province is ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

. It is known from a partial skeleton,

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

DML-LCA 9701-IV, found at the bottom of an assemblage of nine dinosaur individuals, lacking most of the tail

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

e, ribs,

pectoral girdle The shoulder girdle or pectoral girdle is the set of bones in the appendicular skeleton which connects to the arm on each side. In humans it consists of the clavicle and scapula; in those species with three bones in the shoulder, it consists of t ...

, and limb bones. ''Shidaisaurus'' was described in

2009 File:2009 Events Collage V2.png, From top left, clockwise: The vertical stabilizer of Air France Flight 447 is pulled out from the Atlantic Ocean; Barack Obama becomes the first African American to become President of the United States; 2009 Iran ...

by Wu and colleagues. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

is ''Shidaisaurus jinae''. Generic name and specific name in combination refer to the Jin-Shidai ("Golden Age") Company that exploits the Jurassic World Park near the site. This

theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...

according to

Gregory Paul Gregory Scott Paul (born December 24, 1954) is an American freelance researcher, author and illustrator who works in paleontology, and more recently has examined sociology and theology. He is best known for his work and research on theropod dino ...

was about long and it weighed around . In 2016 another estimation listed it higher at 7.1 meters (23.3 feet) long and 950 kilograms (2,094 lbs). It is the oldest Allosauroid known to date.

References

Metriacanthosaurids Middle Jurassic dinosaurs of Asia Fossil taxa described in 2009 Taxa named by Philip J. Currie Paleontology in Yunnan {{theropod-stub